[1] H. Brezis M. Crandall, A. Pazy: Perturbations of nonlinear maximal monotone sets in Banach spaces. Comm. Pure Appl. Math. 23 (1970), 123 - 144. DOI 10.1002/cpa.3160230107 | MR 0257805

[2] S. Burýšek: On spectra of nonlinear operators. Comment. Math. Univ. Carolinae II (1970), 727-743. MR 0288639

[3] B. Calvert, K. Gustafson: Multiplicative perturbation of nonlinear m-accretive operators. J. Functional Analysis 10 (1972), 149-158. DOI 10.1016/0022-1236(72)90046-8 | MR 0341200 | Zbl 0236.47048

[4] M. Crandall, T. Liggett: Generation of semi-groups of nonlinear transformations on general Banach spaces. Amer. J. Math. 93 (1971), 265 - 298. DOI 10.2307/2373376 | MR 0287357 | Zbl 0226.47038

[5] M. Crandall, A. Pazy: Nonlinear semi-groups of contractions and dissipative sets. J. Functional Analysis 3 (1969), 376-418. DOI 10.1016/0022-1236(69)90032-9 | MR 0243383

[6] J. Dieudonné: Foundations of Modern Analysis. Academic Press, New York and London, 1969. MR 0349288

[7] E. Hille, R. Phillips: Functional Analysis and Semi-groups. rev. ed., Amer. Math. Soc. Coll. Pub., Vol. XXXI, 1957. MR 0089373

[8] R. Kačurovskii: The regular points, spectrum, and eigenfunctions of nonlinear operators. Soviet Math. Doki. 10 (1969), 1101-1104.

[9] T. Kato: Perturbation Theory for Linear Operators. Springer-Verlag, New York, 1966. MR 0203473 | Zbl 0148.12601

[10] T. Kato: Accretive operators and nonlinear evolution equations in Banach spaces. Proc. Symp. Pure Appl. Math. 18, Part I, Amer. Math. Soc., Providence, Rhode Island, 1968, 138-161. MR 0271782

[11] M. Krasnoselskii: Topological Methods in the Theory of Nonlinear Integral Equations. Macmillan, New York, 1964. MR 0159197

[12] R. Martin: unpublished lecture notes.

[13] L. May: Localizing the spectrum. Рас. Jour. Math. 44 (1973), 211 - 218. MR 0315540 | Zbl 0255.47070

[14] M. Nashed: Differentiability and related properties of nonlinear operators: some aspects of the role of differentials in nonlinear functional analysis. Nonlinear Functional Analysis and Applications, Publ. No. 26, Math. Res. Center, The University of Wisconsin, Academic Press, New York and London, 1971. MR 0276840

[15] J. Neuberger: Existence of a spectrum for nonlinear transformations. Рас. J. Math. 31 (1969), 157-159. MR 0259696 | Zbl 0182.47203

[16] T. Saaty: Modern Nonlinear Equations. Mc Graw-Hill, New York, 1967. MR 0218160 | Zbl 0148.28202

[17] K. Yosida: Functional Analysis. Springer-Verlag, New York, 2nd Edition, 1968. MR 0239384

[18] E. Zarantonello: The closure of the numerical range contains the spectrum. Bull. Amer. Math. Soc. 70 (1964), 781-787. DOI 10.1090/S0002-9904-1964-11237-4 | MR 0173176 | Zbl 0137.32501

[19] E. Zarantonello: The closure of the numerical range contains the spectrum. Рас. J. Math. 22 (1967), 575-595. MR 0229079 | Zbl 0152.34602